Insomnia is one of the most common reasons for referral to mental health services in active duty personnel. Chronic insomnia often persists post-deployment, contributes to poor mental and physical health outcomes, and requires targeted interventions. Effective behavioral treatments of insomnia have not been adapted and tested for the treatment of chronic insomnia comorbid to combat-related mental disorders and stress reactions. In addition, effective behavioral insomnia treatments are typically delivered over an 8-week period. This format may not be easily exportable to primary and community care settings where military returnees and veterans seek help. The goal of this R34 Exploratory Clinical Research Grant is to adapt and test the effects of a 4- week behavioral treatment that targets chronic insomnia (lasting >1 month) in service members returning from Operation Iraqi Freedom (OIF) and Operation Enduring Freedom (OEF), and who present with the typical psychiatric comorbidities associated of combat-related anxiety and mood disorders and stress reactions. We call this intervention the Brief Behavioral Treatment of Insomnia for Military Veterans (BBTI-MV). The proposed study includes two phases. Phase I aims at iteratively adapting and refining a treatment manual for insomnia in OIF/OEF military returnees. Phase II involves a pilot randomized controlled trial with 40 OIF/OEF returnees (men and women), and who meet diagnostic criteria for primary insomnia, without psychiatric and medical comorbidities as exclusion criteria. Participants will be randomized to either BBTI-MV (n = 20), or to information control (IC) condition (n= 20). Outcomes will be assessed at the end of the acute intervention period (4 weeks), and six months post-intervention. Outcomes of interest include self-report, diary, and actigraphic sleep measures, as well as measures of PTSD, anxiety, and depression, and perceived physical health. Data derived from this study will inform the anticipated R01 application aimed at conducting an insomnia treatment effectiveness study in a large sample of military veterans who present with the typical conditions characteristics of the broad spectrum of combat-related mental disorders and stress reactions. The proposed study directly addresses the research objective of the R34 mechanism by proposing to adapt, iteratively refine, and pilot test a new and adapted intervention for insomnia in military returnees from Operation Iraqi Freedom and Operation Enduring Freedom. Insomnia is a highly prevalent condition in active and ex-service members who experience stress reactions, anxiety, or mood disorders. The development of brief behavioral treatments for insomnia that are easily transportable to care settings where veterans seek help can improve mental and physical health outcomes in ex-service members.